-19- at the level of the RPG is considered as an acceptable risk for a lifetime. The RPG's for the population are expressed in terms of annual exposure except for the gonads where the ICRP recommended value of 5 rems in 30 years is used. FRC states that the operational mechanism described for application of criteria to limit the whole body dose for individuals to 0.5 rem per year and to limit exposure of a suitable sample of the population to 0.17 rem per year is likely to assure that the gonadal exposure guide will not be exceeded. Environmental radiation monitoring is a necessary part of complying with the RPG guidance. The intensity and frequency of measurements is to be determined by the need to be able to detect sharply rising trends and to provide prompt and reliable information on the effectiveness of control actions. Radioactive source control actions and monitoring efforts are to increase as predicted exposures move upward through a range of values and approach the numerical value of the RPG. A sharply rising trend approaching the RPG would suggest strong and prompt action. The magnitude of the action should be related to the degree of likelihood that the RPG would be exceeded. The child, infant, and unborn infant are identified as being more sensitive to radiation than the adult. Exposures to be compared with the guidance are to be derived for the most sensitive members in the population. The guide for the individual applies when individual exposures are known; otherwise, the guide for a suitable sample a eae, SOATER IM aft ep et ae ‘ me DT ee x vty? > : CEana eer ome m, Se geemrgenre ere FRASIERae ee cera “he Pe at ed Mh et rIN , Say te ge Met, 4 mE Aateus fee Te TR oe Se : mye an aoa we! ; a 4 oh pegs